According to the latest report from SPORT, Simeone has set tactics for Yamal, wanting to force him to get a yellow card and miss the second leg.

According to reports, Simeone has clarified the core tactical and psychological goals against Barcelona in the first leg. He wants to force Yamal to get a yellow card. The latter has accumulated four yellow cards in this Champions League season. Another card will trigger a suspension, missing the second leg.
With Raphinha's injury absence, Barcelona has lost one of its two major breakthroughs, and the depth threat of the offense has been greatly reduced. Because of this, according to Atletico Madrid's coaching staff analysis, freezing Yamal has become a strategic priority.
Barcelona, lacking two main wingers, will have a significant decrease in their ability to create numerical advantages on the wing and tear through the opponent's defense - and the Metropolitano Stadium has always been Atletico Madrid's "fortress" in European knockout matches.
Atletico Madrid's coaching staff is designing a set of "high-intensity + stage-by-stage" marking plan for Yamal: planning to implement tactical fouls early on the right to cut off his dribbling and prevent him from going deep into the end line.
Simultaneously, they will frequently use double-teaming to force him to receive the ball with his back to the gate or get into unfavorable positions, and may even arrange experienced players to conduct "controllable provocations" to force Yamal to become emotionally overwhelmed and distracted.
Simeone has used similar tactics in previous games, but this time the background is more critical: Atletico Madrid needs to weaken Barcelona's offensive firepower in the second leg - at that time, the home advantage and the high-pressure atmosphere of the Metropolitano Stadium are often the key to victory.
